diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index ef481ce11069..cced6f935e5c 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -7199,7 +7199,9 @@ public CodegenParameter fromFormProperty(String name, Schema propertySchema, Set
         codegenParameter.nameInPascalCase = camelize(codegenParameter.paramName);
         codegenParameter.nameInSnakeCase = CaseFormat.UPPER_CAMEL.to(CaseFormat.UPPER_UNDERSCORE, codegenParameter.nameInPascalCase);
         codegenParameter.nameInLowerCase = codegenParameter.paramName.toLowerCase(Locale.ROOT);
-
+        codegenParameter.isContainer = codegenProperty.isContainer;
+        codegenParameter.containerType = codegenProperty.containerType;
+        codegenParameter.containerTypeMapped = codegenProperty.containerTypeMapped;
         codegenParameter.dataFormat = codegenProperty.dataFormat;
         // non-array/map
         updateCodegenPropertyEnum(codegenProperty);
@@ -7266,7 +7268,15 @@ public CodegenParameter fromFormProperty(String name, Schema propertySchema, Set
                 }
             }
         } else if (ModelUtils.isTypeObjectSchema(ps)) {
-            if (ModelUtils.isFreeFormObject(ps)) {
+            if (ModelUtils.isMapSchema(ps)) {
+                codegenParameter.isMap = true;
+                codegenParameter.additionalProperties = codegenProperty.additionalProperties;
+                codegenParameter.setAdditionalPropertiesIsAnyType(codegenProperty.getAdditionalPropertiesIsAnyType());
+                codegenParameter.items = codegenProperty.items;
+                codegenParameter.isPrimitiveType = false;
+                codegenParameter.items = codegenProperty.items;
+                codegenParameter.mostInnerItems = codegenProperty.mostInnerItems;
+            } else if (ModelUtils.isFreeFormObject(ps)) {
                 codegenParameter.isFreeFormObject = true;
             }
         } else if (ModelUtils.isNullType(ps)) {
@@ -7275,10 +7285,10 @@ public CodegenParameter fromFormProperty(String name, Schema propertySchema, Set
         } else if (ModelUtils.isArraySchema(ps)) {
             Schema inner = getSchemaItems((ArraySchema) ps);
             CodegenProperty arrayInnerProperty = fromProperty("inner", inner, false);
+            codegenParameter.isArray = true;
             codegenParameter.items = arrayInnerProperty;
             codegenParameter.mostInnerItems = arrayInnerProperty.mostInnerItems;
             codegenParameter.isPrimitiveType = false;
-            codegenParameter.isContainer = true;
             // hoist items data into the array property
             // TODO this hoisting code is generator specific and should be isolated into updateFormPropertyForArray
             codegenParameter.baseType = arrayInnerProperty.dataType;
diff --git a/modules/openapi-generator/src/test/resources/3_0/cpp-ue4/petstore.yaml b/modules/openapi-generator/src/test/resources/3_0/cpp-ue4/petstore.yaml
new file mode 100644
index 000000000000..ac21aadd1b04
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/cpp-ue4/petstore.yaml
@@ -0,0 +1,717 @@
+swagger: '2.0'
+info:
+  description: 'This is a sample server Petstore server. For this sample, you can use the api key `special-key` to test the authorization filters.'
+  version: 1.0.0
+  title: OpenAPI Petstore
+  license:
+    name: Apache-2.0
+    url: 'https://www.apache.org/licenses/LICENSE-2.0.html'
+host: petstore.swagger.io
+basePath: /v2
+tags:
+  - name: pet
+    description: Everything about your Pets
+  - name: store
+    description: Access to Petstore orders
+  - name: user
+    description: Operations about user
+schemes:
+  - http
+paths:
+  /fake/map-body-parameter:
+    post:
+      tags:
+        - fake
+      summary: Test maps as body parameter
+      description: ''
+      operationId: testMapAsBodyParameter
+      parameters:
+        - in: body
+          name: body
+          required: true
+          schema:
+            type: object
+            properties:
+              Attributes:
+                type: object
+                additionalProperties:
+                  type: string
+                  nullable: true
+      responses:
+        '400':
+          description: Invalid input
+  /pet:
+    post:
+      tags:
+        - pet
+      summary: Add a new pet to the store
+      description: ''
+      operationId: addPet
+      consumes:
+        - application/json
+        - application/xml
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: Pet object that needs to be added to the store
+          required: true
+          schema:
+            $ref: '#/definitions/Pet'
+      responses:
+        '405':
+          description: Invalid input
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+    put:
+      tags:
+        - pet
+      summary: Update an existing pet
+      description: ''
+      operationId: updatePet
+      consumes:
+        - application/json
+        - application/xml
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: Pet object that needs to be added to the store
+          required: true
+          schema:
+            $ref: '#/definitions/Pet'
+      responses:
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Pet not found
+        '405':
+          description: Validation exception
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+  /pet/findByStatus:
+    get:
+      tags:
+        - pet
+      summary: Finds Pets by status
+      description: Multiple status values can be provided with comma separated strings
+      operationId: findPetsByStatus
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: status
+          in: query
+          description: Status values that need to be considered for filter
+          required: true
+          type: array
+          items:
+            type: string
+            enum:
+              - available
+              - pending
+              - sold
+            default: available
+          collectionFormat: csv
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            type: array
+            items:
+              $ref: '#/definitions/Pet'
+        '400':
+          description: Invalid status value
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+  /pet/findByTags:
+    get:
+      tags:
+        - pet
+      summary: Finds Pets by tags
+      description: 'Multiple tags can be provided with comma separated strings. Use tag1, tag2, tag3 for testing.'
+      operationId: findPetsByTags
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: tags
+          in: query
+          description: Tags to filter by
+          required: true
+          type: array
+          items:
+            type: string
+          collectionFormat: csv
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            type: array
+            items:
+              $ref: '#/definitions/Pet'
+        '400':
+          description: Invalid tag value
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+      deprecated: true
+  '/pet/{petId}':
+    get:
+      tags:
+        - pet
+      summary: Find pet by ID
+      description: Returns a single pet
+      operationId: getPetById
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet to return
+          required: true
+          type: integer
+          format: int64
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/Pet'
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Pet not found
+      security:
+        - api_key: []
+    post:
+      tags:
+        - pet
+      summary: Updates a pet in the store with form data
+      description: ''
+      operationId: updatePetWithForm
+      consumes:
+        - application/x-www-form-urlencoded
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet that needs to be updated
+          required: true
+          type: integer
+          format: int64
+        - name: name
+          in: formData
+          description: Updated name of the pet
+          required: false
+          type: string
+        - name: status
+          in: formData
+          description: Updated status of the pet
+          required: false
+          type: string
+      responses:
+        '405':
+          description: Invalid input
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+    delete:
+      tags:
+        - pet
+      summary: Deletes a pet
+      description: ''
+      operationId: deletePet
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: api_key
+          in: header
+          required: false
+          type: string
+        - name: petId
+          in: path
+          description: Pet id to delete
+          required: true
+          type: integer
+          format: int64
+      responses:
+        '400':
+          description: Invalid pet value
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+  '/pet/{petId}/uploadImage':
+    post:
+      tags:
+        - pet
+      summary: uploads an image
+      description: ''
+      operationId: uploadFile
+      consumes:
+        - multipart/form-data
+      produces:
+        - application/json
+      parameters:
+        - name: petId
+          in: path
+          description: ID of pet to update
+          required: true
+          type: integer
+          format: int64
+        - name: additionalMetadata
+          in: formData
+          description: Additional data to pass to server
+          required: false
+          type: string
+        - name: file
+          in: formData
+          description: file to upload
+          required: false
+          type: file
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/ApiResponse'
+      security:
+        - petstore_auth:
+            - 'write:pets'
+            - 'read:pets'
+  /store/inventory:
+    get:
+      tags:
+        - store
+      summary: Returns pet inventories by status
+      description: Returns a map of status codes to quantities
+      operationId: getInventory
+      produces:
+        - application/json
+      parameters: []
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            type: object
+            additionalProperties:
+              type: integer
+              format: int32
+      security:
+        - api_key: []
+  /store/order:
+    post:
+      tags:
+        - store
+      summary: Place an order for a pet
+      description: ''
+      operationId: placeOrder
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: order placed for purchasing the pet
+          required: true
+          schema:
+            $ref: '#/definitions/Order'
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/Order'
+        '400':
+          description: Invalid Order
+  '/store/order/{orderId}':
+    get:
+      tags:
+        - store
+      summary: Find purchase order by ID
+      description: 'For valid response try integer IDs with value <= 5 or > 10. Other values will generate exceptions'
+      operationId: getOrderById
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: orderId
+          in: path
+          description: ID of pet that needs to be fetched
+          required: true
+          type: integer
+          maximum: 5
+          minimum: 1
+          format: int64
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/Order'
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Order not found
+    delete:
+      tags:
+        - store
+      summary: Delete purchase order by ID
+      description: For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors
+      operationId: deleteOrder
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: orderId
+          in: path
+          description: ID of the order that needs to be deleted
+          required: true
+          type: string
+      responses:
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Order not found
+  /user:
+    post:
+      tags:
+        - user
+      summary: Create user
+      description: This can only be done by the logged in user.
+      operationId: createUser
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: Created user object
+          required: true
+          schema:
+            $ref: '#/definitions/User'
+      responses:
+        default:
+          description: successful operation
+  /user/createWithArray:
+    post:
+      tags:
+        - user
+      summary: Creates list of users with given input array
+      description: ''
+      operationId: createUsersWithArrayInput
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: List of user object
+          required: true
+          schema:
+            type: array
+            items:
+              $ref: '#/definitions/User'
+      responses:
+        default:
+          description: successful operation
+  /user/createWithList:
+    post:
+      tags:
+        - user
+      summary: Creates list of users with given input array
+      description: ''
+      operationId: createUsersWithListInput
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: List of user object
+          required: true
+          schema:
+            type: array
+            items:
+              $ref: '#/definitions/User'
+      responses:
+        default:
+          description: successful operation
+  /user/login:
+    get:
+      tags:
+        - user
+      summary: Logs user into the system
+      description: ''
+      operationId: loginUser
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: username
+          in: query
+          description: The user name for login
+          required: true
+          type: string
+        - name: password
+          in: query
+          description: The password for login in clear text
+          required: true
+          type: string
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            type: string
+          headers:
+            X-Rate-Limit:
+              type: integer
+              format: int32
+              description: calls per hour allowed by the user
+            X-Expires-After:
+              type: string
+              format: date-time
+              description: date in UTC when token expires
+        '400':
+          description: Invalid username/password supplied
+  /user/logout:
+    get:
+      tags:
+        - user
+      summary: Logs out current logged in user session
+      description: ''
+      operationId: logoutUser
+      produces:
+        - application/xml
+        - application/json
+      parameters: []
+      responses:
+        default:
+          description: successful operation
+  '/user/{username}':
+    get:
+      tags:
+        - user
+      summary: Get user by user name
+      description: ''
+      operationId: getUserByName
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: username
+          in: path
+          description: 'The name that needs to be fetched. Use user1 for testing.'
+          required: true
+          type: string
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/User'
+        '400':
+          description: Invalid username supplied
+        '404':
+          description: User not found
+    put:
+      tags:
+        - user
+      summary: Updated user
+      description: This can only be done by the logged in user.
+      operationId: updateUser
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: username
+          in: path
+          description: name that need to be deleted
+          required: true
+          type: string
+        - in: body
+          name: body
+          description: Updated user object
+          required: true
+          schema:
+            $ref: '#/definitions/User'
+      responses:
+        '400':
+          description: Invalid user supplied
+        '404':
+          description: User not found
+    delete:
+      tags:
+        - user
+      summary: Delete user
+      description: This can only be done by the logged in user.
+      operationId: deleteUser
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - name: username
+          in: path
+          description: The name that needs to be deleted
+          required: true
+          type: string
+      responses:
+        '400':
+          description: Invalid username supplied
+        '404':
+          description: User not found
+securityDefinitions:
+  petstore_auth:
+    type: oauth2
+    authorizationUrl: 'http://petstore.swagger.io/api/oauth/dialog'
+    flow: implicit
+    scopes:
+      'write:pets': modify pets in your account
+      'read:pets': read your pets
+  api_key:
+    type: apiKey
+    name: api_key
+    in: header
+definitions:
+  Order:
+    title: Pet Order
+    description: An order for a pets from the pet store
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      petId:
+        type: integer
+        format: int64
+      quantity:
+        type: integer
+        format: int32
+      shipDate:
+        type: string
+        format: date-time
+      status:
+        type: string
+        description: Order Status
+        enum:
+          - placed
+          - approved
+          - delivered
+      complete:
+        type: boolean
+        default: false
+    xml:
+      name: Order
+  Category:
+    title: Pet category
+    description: A category for a pet
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+    xml:
+      name: Category
+  User:
+    title: a User
+    description: A User who is purchasing from the pet store
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      username:
+        type: string
+      firstName:
+        type: string
+      lastName:
+        type: string
+      email:
+        type: string
+      password:
+        type: string
+      phone:
+        type: string
+      userStatus:
+        type: integer
+        format: int32
+        description: User Status
+    xml:
+      name: User
+  Tag:
+    title: Pet Tag
+    description: A tag for a pet
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+    xml:
+      name: Tag
+  Pet:
+    title: a Pet
+    description: A pet for sale in the pet store
+    type: object
+    required:
+      - name
+      - photoUrls
+    properties:
+      id:
+        type: integer
+        format: int64
+      category:
+        $ref: '#/definitions/Category'
+      name:
+        type: string
+        example: doggie
+      photoUrls:
+        type: array
+        xml:
+          name: photoUrl
+          wrapped: true
+        items:
+          type: string
+      tags:
+        type: array
+        xml:
+          name: tag
+          wrapped: true
+        items:
+          $ref: '#/definitions/Tag'
+      status:
+        type: string
+        description: pet status in the store
+        enum:
+          - available
+          - pending
+          - sold
+    xml:
+      name: Pet
+  ApiResponse:
+    title: An uploaded response
+    description: Describes the result of uploading an image resource
+    type: object
+    properties:
+      code:
+        type: integer
+        format: int32
+      type:
+        type: string
+      message:
+        type: string